1. Field of the Invention
The invention relates to an insulation displacement connector, particularly to an insulation displacement connector that can precisely and correctly terminate a multi-conductor cable while an improper deformation of the outer insulation piercing points of the piercing devices on the outermost contacts can be prevented.
2. The Prior Art
Insulation displacement connectors, also known as flat cable connectors or ribbon cable connectors, are widely known by those skilled in the art of connectors. U.S. Pat. Nos. 4,938,711 and 4,902,243 disclose two prior art connectors of this kind that terminate cables by means of piercing devices on contacts. These piercing devices separate cable conductors upon insertion and cut away the insulation surrounding them when connector housings and termination covers are connected. FIG. 1 is a partially cut-away, elevational view generally showing one of the two prior art connectors used to terminate a ribbon cable. FIG. 2 is an enlarged schematic view of a part of FIG. 1, showing the details of two piercing devices on one of the outermost contacts and a neighboring contact respectively, wherein the two piercing devices are inserted into the ribbon cable.
Referring to FIGS. 1 and 2, the connector includes a number of contacts 70 attached to a connector housing (not labeled). Each contact 70 has a piercing device at the end distant to the connector housing. Each piercing device has a pair of insulation piercing points. One of the outermost contacts has a piercing device indicated by reference number 701 that is composed of an outer and inner insulation piercing points 7011 and 7012. When the connector housing is connected with a termination cover (not labeled) to terminate the ribbon cable, the piercing devices are first inserted into the ribbon cable to separate conductors (not labeled), as shown by FIG. 2. Further insertion of the piercing devices causes the insulation surrounding the conductors to be cut away and the insulation piercing points to engage with the conductors, whereby the connector and the ribbon cable are mechanically and electrically connected.
The above mentioned prior art connector is found to have the disadvantages as set forth below.
First, when the piercing devices are inserted through the ribbon cable to separate the conductors and cut away the insulation surrounding them, the movement of the outer insulation piercing points of the piercing devices on the outermost contacts, which include the insulation piercing point 7011, cannot always be properly restrained and guided. During such operation, this may cause the concerned insulation piercing points to become improperly deformed and have poor or no engagement with corresponding conductors.
Secondly, with the advancement of computer technology, insulation displacement connectors are required to have more contacts placed in smaller and smaller connectors (i.e. high density connectors). However, the structure of the prior art connector is not suitable for such a purpose since the prior art connector lacks a locating member which can securely fix the position of the piercing devices to make sure that when the connector terminates the ribbon cable, the piercing devices can always precisely and correctly engage with the conductors in the ribbon cable. An imprecise engagement between the piercing devices and the conductors may cause a poor signal transmission between the cable and the connector.
Therefore, one objective of the invention is to provide an insulation displacement connector whose outer insulation piercing points of the piercing devices on the outermost contacts can always be properly restrained and guided when the connector terminates a ribbon cable.
Another objective of the invention is to provide an insulation displacement connector equipped with a locating member for securely fixing piercing devices in position so that when the connector terminates a ribbon cable, the piercing devices can always precisely and correctly engage with the conductors in the cable. Thus, the insulation displacement connector according to the present invention can also function well when it is constructed as a high density connector.